Best hard riddles for teens

interviewcleansimple

What is unusual about the following words: revive, banana, grammar, voodoo, assess, potato, dresser, uneven?
Take the first letter of each word and place it at the end. It will spell the same word backwards.
73.79 %
100 votes
logictrickystoryclever

A man and woman run through a field holding hands. They bound toward the sunset, happy as can be. Suddenly, the man moves off of his straight-line course and starts veering to his left. At the same time, the woman begins running off to her right. They continue this for a full minute, but never let go of each others' hands. How is this possible?
The man was facing forward, but the woman was running backwards. The man's right hand was holding the woman's right hand. They both veered in the same geographic direction, but it was the man's left and the woman's right because the woman was running backwards.
73.79 %
100 votes
cleansimple

Brothers, all pair up; Bodies firm and tall. You only care to eat the solid food, And don’t care to eat the soup.
Chopsticks
73.64 %
59 votes
logicmath

A farmer lived in a small village. He had three sons. One day he gave $100 dollars to his sons and told them to go to market. The three sons should buy 100 animals for $100 dollars. In the market there were chickens, hens and goats. Cost of a goat is $10, cost of a hen is $5 and cost of a chicken is $0.50. There should be at least one animal from each group. The farmer’s sons should spend all the money on buying animals. There should be 100 animals, not a single animal more or less! What do the sons buy?
They purchased 100 animals for 100 dollars. $10 spent to purchase 1 goat. $45 spent to purchase 9 hens. $45 spent to purchase 90 chickens.
73.64 %
95 votes
logicmathsimple

Two trains are traveling toward each other on the same track, each at 60 miles per hour. When they are exactly 120 miles apart, a fly takes off from the front of one of the trains, flying toward the other train at a constant rate of 100 miles per hour. When the fly reaches the other train, it instantly changes directions and starts flying toward the other train, still at 100 miles per hour. It keeps doing this back and forth until the trains finally collide. If you add up all the distances back and forth that the fly has travelled, how much total distance has the fly travelled when the trains finally collide?
The fly has travelled exactly 100 miles. We can figure this out using some simple math. Becuase the trains are 120 miles apart when the fly takes off, and are travelling at 60 mph each, they will collide in exactly 1 hour. This gives the fly exactly 1 hour of flying time, going at a speed of 100 miles per hour. Thus, the fly will travel 100 miles in this hour.
73.58 %
77 votes
logicsimpleclean

Six glasses are in a row. The first three are filled with milk and the last three are empty. By moving only one glass, can you arrange them so that the full and the empty glasses alternate?
Just pour full glass of milk at 2nd position in 5th glass(empty) and keep that empty glass back at 2nd position. Then full and empty glasses are at alternate positions.
73.40 %
72 votes